The present invention relates to a current collecting system for supplying power to vehicles such as railway vehicles and particularly to high-speed vehicles such as linear motor cars.
Railway and other vehicles powered by electricity are fed with electric power from power supply members installed on the ground including trolley wires. A problem observed in the current collection of this type is that the contact members of the current collecting system are sometimes brought out of engagement with the power supply member. As is well known in the art, this occurs more frequently as the travelling speed of the vehicle is increased. Disengagement of the contact members from the power supply member brings about drawbacks in that the power supply is irregular and hence unstable, that arcs generated upon disengagement melt the contact surfaces and form projections and recesses on the surfaces of the power supply member with which the contact members are held in sliding engagement, and that the sliding surfaces of the power supply member are further damaged owing to this irregularity, the power supply member being broken in the worst case.
To avoid the problem discussed above, there has been increased precision in the machining and installing of a power supply member so that its sliding surfaces may be straightened and to reduce the weights of movable members included in a current collecting system while increasing the contact pressure to thereby improve the following ability as a result of a decrease in the period of natural vibration. Power supply members are available in two different forms: wires and rigid members. Wires can be installed with an increased precision relatively easily, but an increase in the contact pressure of contact members engaged with the wires will not only promote wear of the contact members and the wires but also result in bowing and tensioning of the wires which may consequently create dangerous conditions. On the other hand, it is not easy to install rigid power supply members while minimizing the irregularity of their alignment, nor to maintain their quality of surface finish after the installation, and the contact pressure of the contact members though it can be sufficiently increased is directly reflected by wear of the contact members. Thus, the upper limit of the speed in which current collection can be done with prior art techniques is in the order of 230-250 km/hr in terms of vehicle speed.